package Observer_Pattern.Cat;

import java.util.ArrayList;

// -*-coding:utf-8 -*-
//人员：刘陆鑫
//班级：19软3
//学号；2019110218
public abstract class AbstractTarget {
    protected ArrayList observers=new ArrayList();
    public void attach(Observer observer){
        observers.add(observer);
    }
    public void detach(Observer observer){
        observers.remove(observer);
    }
    public abstract void notice();

}
